Matt Romanowski

The ultimate lat G is whatever the chassis, tires, track geography, etc will allow.. The braking event prior to it does not affect it once the car has taken a set in the corner. It will be what it is. This assumes you get the car to a steady state. The transient parts of the suspension movement up to the steady state (and after) can be changed by shocks, chassis tuning, driver inputs, etc.

Now. since the high end of the scale is a fixed number, we want to try and make it make everything leading up to it as high as possible. That means using all the traction we have available. Since the tire has a finite amount of traction, we can use all of it for braking, blend into corner, then all of it for corning (the traction circle theory).

If you look at lots of data, braking usually has the most time in it. For folks who have a lot of low hanging fruit, it's honestly seconds per lap. For people who are at the pointy end of the field, it can still be tenths of a second. Then the difference between the fast and really fast drivers lies in the blending of the braking event to the cornering event. That is where you see the rise and sustained height of G sum curve.

Now, I think the early, softer braking that Dave advocates is a method that helps people to make the blending of braking to cornering easier. Ultimately, it's not as fast as the later, harder braking perfectly blended into the cornering phase. The ability to brake just the right amount, at just the right time, slowing releasing as you start turning in and finally releasing all the way as the car is on the edge of spinning, is a very hard skill to master. Most of us try for this for a lifetime and only achieve it in fits and spurts. The great race drivers are able to achieve this all the time.

Many folks can do one or the other, but not combine them. That is what separates the folks who get paid to drive versus those of us who pay to drive.

cetom

thank you very much , i appreciate the conversation

Matt Romanowski

Me too! It's great to have a group of people interested in data and driving enough to have a good conversation.

Matt Romanowski

Here are two graphs to show the difference it can make in time. The first shows the delta in brake distance and the second shows the time difference that it made.

dan212

I don't think dave is advocating the slower / earlier braking just as a learning tool.

His point was to maintain balance with the car. Same as jackie Stewart said almost 40 years ago.. Doesn't mean avoiding threshold braking. It means getting there without unsettling the car. Perhaps by doing so actually slowly the car down less in the long run.

You can carry speed deeper. And carry more speed NET/NET.

cetom

but matt ,i think your graphs actually are evidence against the late , hard brake . the blue line brakes later and indeed has more speed early in braking . and based on where your cursor is placed indeed blue line picks up a bit of time in a very short segment of track . but look just passed your second cursor . blue line min speed in the corner is slower than orange and orange gets on the throttle sooner , carries more speed down the whole next straight. moreover look at the slope of blue and orange as speed falls . orange is steady and straight . blue "bellies out" near the corner . blue is coming off the brakes ,is trying to modulate but still oveslows the car .
as it pertains to this discussion blue would have a more circular friction circle , but because the velocity is less at the apex i believe his max g would be less . also his Gsum would have a lower peak. but he would feel like he was fast and he would be on the outer edge of the friction circle.
all i am saying is that the holy grail of the round friction circle maybe should be rethought .
i also want to add that i am no expert and certainly not a professional , just a guy who wants to learn how to drive better and will do this with the guidance of data. i think i am reading your graphs correctly but i could be wrong
thanks

ProCoach

The quickest drivers have rounder friction circles and no dip in GSum at or just before turn-in. They also achieve LongG max in a finite, measured and known time.

If you can't do that, try and develop a workflow and targeted strategy that will allow you to execute so that deficit is less. If you can't to that, after verifying that you are executing well, fix the car.

This is not rocket science, gentlemen...

ProCoach

Great post! Sounds familiar! <grin>

Veloce Raptor

THIS is EXACTLY what I mean. Thanks, Dan!

Perhaps I have been uncharacteristically inarticulate in this thread and/or in the article. If so, apologies. I am not advocating being a pansy under braking, nor wasting time or real estate under braking. Quite the opposite. I am trying to advocate ways that will reduce the amount of real estate at vMin, and the amount of time we are at vMin. One way to do this is to have a more balanced, stable chassis, as Dan says above. One way to do THIS is to not add so much drama to the car via that brake pedal.

TXE36

I was waiting for this. That's exactly how I understood it after listening to the explanation in VR's classroom.

Perhaps another way of thinking of it is the chassis "taking a set" under braking much like the chassis takes a set in a turn. Once the transition to the set has occurred one can take advantage of it. Much like turning the wheel roughly, rough application of the brake stands the car on its nose upsets this process.

Let me know if I'm out in the weeds.

-Mike

Veloce Raptor

Not in the weeds, Mike Thanks for paying attention!

tkerrmd

Will look forward to them

Veloce Raptor

New article is up:

https://clubregistration.net/raceCoach/

Veloce Raptor

Next iteration is up:

http://clubregistration.net/raceCoach/

certz

"Slowly adding more steering at turn-in and apex..." Sounds so familiar, like someone was just saying this to me in my helmet

Thanks again Dave